Reference Manual

1−21
After going through all the criteria for a given
application, the selection process may point to
several types of valves. From there on, selection
becomes a matter of price versus capability,
coupled with the inevitable personal and
institutional preferences. As no single control valve
package is cost-effective over the full range of
applications, it is important to keep an open mind
to alternative choices.
Table 1-2. Major Categories and Subcategories of Control Valves with Typical General Characteristics
Valve Style
Main
Characteristics
Typical Size
Range,
inches
Typical
Standard Body
Materials
Typical Standard
End Connection
Typical
Pressure
Ratings
Relative Flow
Capacity
Relative
Shutoff
Capability
Regular
Sliding-stem
Heavy Duty
Versatile
1 to 24
Carbon Steel
Cast Iron
Stainless
ANSI Flanged
Welded
Screwed
To ANSI 2500 Moderate Excellent
Bar Stock
Machined from Bar
Stock
½ to 3
Variety of Alloys
Flangeless
Screwed
To ANSI 600 Low Excellent
Economy
Sliding-stem
Light Duty
Inexpensive
½ to 2
Bronze
Cast Iron
Carbon Steel
Screwed To ANSI 125 Moderate Good
Thru-Bore
Ball
On-Of f Service 1 to 24
Carbon Steel
Stainless
Flangeless To ANSI 900 High Excellent
Partial Ball
Characterized for
Throttling
1 to 24
Carbon Steel
Stainless
Flangeless
Flanged
To ANSI 600 High Excellent
Eccentric Plug Erosion Resistance 1 to 8
Carbon Steel
Stainless
Flanged To ANSI 600 Moderate Excellent
Swing-Thru
Butterfly
No Seal 2 to 96
Carbon Steel
Cast Iron
Stainless
Flangeless
Lugged
Welded
To ANSI 2500 High Poor
Lined Butterfly
Elastomer or
TFE Liner
2 to 96
Carbon Steel
Cast Iron
Stainless
Flangeless
Lugged
To ANSI 300 High Good
High
Performance
Butterfly
Offset Disk
General Service
2 to 72
Carbon Steel
Stainless
Flangeless
Lugged
To ANSI 600 High Excellent